Table 1.
Spindola-Franco extended classification of dual LAD variants [15]. AIS: anterior interventricular sulcus. LAD: left anterior descending artery. LMCA: left main coronary artery. LCS: left coronary sinus. LV: left ventricle. RCA: right coronary artery. RV: right ventricle. RCS: right coronary sinus. RVOT: right ventricle outflow tract. PA: pulmonary artery.
| Short LAD | Long LAD | |
|---|---|---|
| I | Originates from the LAD proper and terminates in the proximal AIS | Originates from the LAD proper, descends on LV side of the proximal AIS and terminates in the distal AIS |
| II | Originates from the LAD proper and terminates in the proximal AIS | Originates from the LAD proper, descends on RV side of the proximal AIS and terminates in the distal AIS |
| III | Originates from the LAD proper and terminates in the proximal AIS | Originates from the LAD proper and terminates in the proximal AIS or in the apical septum |
| IV | Originates from the LMCA and terminates in the proximal AIS | Originates from RCA. courses along an anomalous prepulmonic course anterior to RVOT and reenters the distal AIS |
| V | Originates from the LCS and terminates in the proximal AIS | Originates from RCS, courses along an intramyocardial course and emerges epicadilly to enter the distal AIS |
| VI | Originates from the LMCA and terminates in the proximal AIS | Originates from the RCA, courses between the RVOT and the aortic root and emerges in distal AIS |
| VII | Originates from the LAD proper and terminates in the proximal AIS | Originates from the LAD proper, courses along the LV side of proximal AIS and terminates in the distal AIS |
| VIII | Originates from the LMCA and terminates in the proximal AIS | Originates from the Mid-RCA, courses along the RV and traverses the apex, terminating in the distal AIS |
| IX | Originates from the LAD proper and terminates in the proximal AIS | Originates from the LAD proper, courses along the LV side of the AIS, enters the distal AIS and terminates before the apex |
| X | Originates from the LMCA and terminates in the proximal AIS | Originates from RCS, courses along an anomalous prepulmonic course anterior to RVOT and reenters the distal AIS |
| XI | Originates from RCS, takes an intramyocardial course and terminates in the proximal AIS | Originates from RCS, courses along an anomalous prepulmonic course anterior to RVOT and reenters the distal AIS |
| XII | Originates from the LMCA (that originates from RCS) and terminates in the proximal AIS | Originates from the RCS, courses anterior to the main PA and terminates in the distal AIS |
| XIII | / | Two long LADS, both of which leave the AIS and course out to the apex (one courses laterally so the other courses medially of the AIS) |